This invention relates in general to plastic injection molding devices and in particular to a new and useful device having means for spraying the mold surfaces of multi-part injection and pressing dies.
The invention provides equipment for spraying the mold surfaces of multi-part injection molding and pressing dies of machines for the production of shaped parts from plasticizable material, in particular dies of a plastic injection molding machine.
In the production of injection molded or pressed pats, e.g. of plastic, plastic-like or ceramic material, by means of multi-part dies, it is usually necessary periodically to spray the mold surfaces forming the mold cavities with a mold release agent, to facilitate the removal of the molding from the die. For this purpose it is known practice to fix spray nozzles on the die or on the machine in such a way that spray medium supplied to them can get onto the mold surfaces when the die is open. But as such machines can operates with a great variety of exchangeable dies, either each die must have its own nozzles to be coupled with a spray medium supply, or the nozzles must be attached on the machine in such a way that they can fulfill their function also for also for greatly varying dies, this being possible usually only approximately. If the dies are changed, they must usually be cleaned before being stored and must be sprayed with an anti-corrosion agent, this being normally done on the machine by means of a hand held spray gun. Not only is this complicated, but it also means the employment of an operator, disadvantage when an automated machine equipped with an automatically controlled handling device for the tool or die change is involved, which could otherwise operate entirely without an operator.